Direction signal system



Dec. 15, 1942. L. B. SMITH i 2,304,963

I DIRECTION SIGNAL SYSTEM Filed April"24, 1941 ZEFT FRONT RIG/l7 FRONT l4 I6 20 22 apps LOWER a: F LOWER BEAM BEAM BEAM BEAM TO PARK MIG L /6H T$ RIGHT REAR Ennentor [avian 2?. 522212711 attorneys Patented Dec. 15, 1942 2,304,963 7 DIRECTION SIGNAL SYSTEM Lucian B. Smith, Flint, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application April 24, 1941, Serial No. 390,031

1 Claim.

My invention relates to direction signal systems of the type used on motor vehicles to give a signal indicating that the driver intends to turn right or left.

An object of my invention is to provide a signal system in which the rear signal light flashes on and off on the side to which the driver intends to turn, and in which the headlight on the same side flashes by alternating between the upper and lower beam filaments.

For further objects of the invention and for a complete understanding thereof reference should be had to the specification and claim. and to the appended drawing.

The single figure of the drawing is a circuit diagram of a signaling system embodying my invention with the various signal lights and headlights shown schematically in their relation to each other.

In the drawing I indicates any source of electrical energy such as a storage battery which may be readily adapted to installation and use in a motor vehicle. The left headlight l2 carries an upper beam filament l4 and a lower beam filament is; the right headlight l8 carries upper lower beam filaments 2B and 22, respectively. The upper beam filaments are normally mounted at the focal point of the reflector, and may be called in-focus filaments. The lower beam filaments are necessarily then out-of-focus filaments. At the rear of the vehicle are mounted left and right rear signal lights 24 and 26, respectively. A lighting switch 28 is provided to complete a circuit between the battery and the lights. A foot switch 30 of conventional design is provided to enable the driver of the vehicle to switch from the upper beam to the lower beam and back again at will. Foot switch 343 carries a movable contact 32 which engages with either of two fixed contacts 34 and 36. A spring 38 biases the movable contact into engagement with fixed contact 34 so that the upper beam filaments are normally in the circuit with the light switch closed. It is understood, of course, that the foot switch itself is only an incidental part of the signaling system of my invention and any conventional switch means for switching from the upper beam filament to the lower may be used. A direction signal switch Ml is provided to enable the driver to make connections to the proper lights to give the signal desired. Switch lll may be of any suitable design but I show it schematically as comprising a shaft or bar 42 of insulating material carrying movable contacts 25, 46, 33, 5D, 52 and 54. Each of these movable contacts is and the conductors connected to them will be arranged to cooperate with any one of three pairs of fixed contacts as shown. These fixed contacts cuit in subsequent paragraphs outlining the operation of my invention.

A flasher or interrupter is indicated generally by 56. The details of this ,fiasher form no part of my invention and any suitable conventional flasher may be used. However, I prefer to use one such as shown in the drawing in which an iron core 58 carries a coil 50 which makes an from core electromagnet having a pole face 62. Mounted on the core 58 in electrical conducting relation therewith is a movable contact 54 arranged to engage either of fixed contacts 36 or 68. A thermal element comprising a fine wire ID is tightly stretched between its contact point with movable contact 64 and insulating bushing 12 in arm 58a of core 58. A resistance M is elece trically connected with thermal element It! at bushing 12. Resistance 14 is electrically connected to fixed contact 68 by a conductor 76.

A brief description of the operation of interrupter 553 is advantageous at this point: thermal element '10 is in tension as stated and normally keeps movable contact 34 in electrical conducting engagement with fixed contact 66 and out of engagement with fixed contact 68. Movable contact 64 is preferably formed of a leaf spring having suitable conducting properties and being biased toward conducting relation with fixed contact 58 in opposition to the bias of the tensioned thermal element 10. For the purposes of this discussion of the operation of interrupter 55, let

it be assumed that the necessary switches are closed to complete conducting paths through the interrupter. With movable contact 54 in engagement with fixed contact 66 as shown in the diagram, current flows from battery to through conductor 78 to iron core 58 which also serves as a conductor. Movable contact 64 is in conducting relation with core 53. There is therefore current fiow through movable contact 64 to fixed contact 65. Current also flows through thermal element i9, resistance 14, wire it, and electromagnet (it. This current flow serves to heat up thermal element l6 causing it to release or relieve its tension, whereupon the normal bias in the spring leaf of movable contact 5 moves this contact out of engagement with fixed contact 65 and into engagement with fixed contact 68. This shift of movable contact 6% is assisted to some extent by the electromagnet 50, which tends to give the motion a snap action to reduce sparking between the contacts. Current flow now is from movable contact 54 to fixed contact 88. This flow short circuits the thermal element H3 and resistance M, giving thermal element a chance to cool. When it has cooled off its tension is restored and it pulls movable contact 64 back into conducting engagement with fixed contact 66 from which point the cycle is repeated. It

will be seen that the various tensions, resistances and the magnet strength can be so apportioned as to give an interrupter frequency of any desired value.

The operation of the signaling device as a whole will nowJce described. Let it be assumed first that the light switch is offi. e., operation of the system under daylight conditions. If the driver wishes to indicate that a left turn is to be made he pushes the direction signal switch toward the left. The circuit thereupon established is as follows: battery I0, conductor I8, core 58, movable contact 64, contact 66, conductor 80, fixed contact 82 at the extreme left of direction signal switch 40, bridging contact 54, fixed contact 84, conductr 85, upper beam filament I4 of left headlight I2, and back to the battery throughthe ground. There is also current flow through thermal element I0, resistance I4, conductor I6, electromagnet 6!), conductor 88, fixed contact 95, bridging contact 45, fixed contact 92, and back to the battery through the ground. As previously explained, this last described circuit heats up thermal element I0 whereupon movable contact 64 isbiased out of engagement with fixed contact 66 and into engagement with fixed contact B8. A circuit is then established as follows: battery Ill, conductor I8, core 58, movable contact 64, fixed contact I38, conductor 94, fixed contact 96, bridging contact 52, fixed contact 98, conductor, I43, lower beam filament I6 of left headlight I2, and back to the battery through the ground. Note that conductor I02 is connected to conductor lllil. This connection establishes the following circuit: conductor I I32,

fixed contact I04, bridging contact 44, fixed contact I06, conductor I83, left rear signal light 24, and. back to the battery through the ground. After thermal element It! is cooled sufiiciently the cycle is repeated. It is evident therefore that the left headlight will flash, but this flashing comprises alternate energizing of the two filaments rather than alternate energizing on and off of a single filament. It is also evident that the left rear signal light will flash, but this flashing is on and off. The right headlight and the right rear sigal lights are unaffected. It may be pointed out here that even with movable contact 64 in engagement with fixed contact 66 there is necessarily a small current flow through thermal element in, resistance I4, conductors Iii and 94, fixed contact 9", bridging contact 52, fixed contact 98, conductor I00, and lower beam filament I6 of headlight I2. Due to this high resistance path, however, the value of this current is not enough to heat filament I6 to in-candescence so that only filament I4 burns. Similarly, the parallel flow through conductor I02 to the left rear signal light under these circumstances is not enough to heat the filament of this light to incandescence. If a right turn is intended under daylight conditions, direction signal switch 40 is moved to the right and the circuit established is the following: battery It, conductor I8, core 58, movable contact 64, fixed contact 66, conductors 80 and I II], fixed contact II2, bridging contact 59, fixed contact H4, conductor H6, upper beam filament 20 of right headlight I8, and back to the battery through the ground. As before, upon heating of thermal element I4, engagement between movable contact 54 and fixed contact 66 is broken and engagement of movable contact 64 and. fixed contact 63 is made, establishing the following circuit from movable contact 64: fixed contact 68, conductors 94 and H8, fixed contact I20, bridging contact 48, fixed contact I22, conductor I24, lower beam filament 22 of right headlight I8, and back to the battery through the ground. It should be noted that conductor I26 is connected to conductor I24 establishing the following circuit from conductor I24: conductor I26, fixed contact I28, bridging contact 44, fixed contact I30, conductor I32, and right rear signal light 26. When direction signal switch 44 is in its extreme right-hand position, movable contact 46 bridges fixed contacts a and 92a thus completing a circuit for electromagnet 64 with the direction signal switch in this position. It is seen then that for a right turn indication the right headlight flashes by alternately energizing the two filaments, and the right rear signal light flashes on and off. The left headlight and left rear signal light remain unaffected.

There may be situations in which the driver of the vehicle will want to drive with the parking lights on. Switch 28 in this case will contact button 21 completing a circuit to the parking lights and also contact 3!. With direction signal switch 40 in its neutral or mid position the circuit is thereby completed to the rear signal lights as follows: battery It, conductor I I, switch 28, fixed contact 3i, conductor I34, fixed contact I36, bridging contact 46, fixed contact I38, conductor I88, left rear signal light 24, and back through the ground. Conductor I34 also goes to fixed contact I45 to complete the following circuit: fixed contact I40, bridging contact 44, fixed contact 42, conductor I32, right rear signal light 25, and back through the ground. If with switch 28 in this position a left turn is indicated, bridging contact 44 is moved out of engagement with fixed contacts I4III42, thus breaking the circuit to the right rear signal light and completing an intermittent circuit to left rear signal light by engaging the two fixed contacts I04 and IE6. In this situation then the circuit completedto left rear signal light would be the same as described above for a left turn. Also, as described above, intermittent circuits will be completed to the upper and lower beam filaments of the left headlight.

If a right turn is indicated with the parking lights on, bridging contact 46 is moved out of engagement with fixed contacts I36-I38, thus breaking the circuit to left rear signal light 24. Simultaneously, bridging contact 44 is moved out of engagement with fixed contacts I4I]I42 and into engagement with fixed contacts I28I3il. Right rear signal light is then in the flasher circuit as described above. The circuit for the right headlight is also as described above.

For night driving, switch 23 will be in engagement with contact 29. Switch 28 will also be in engagement with contact 3I completing circuits to the left and right rear signal lights as described above. With switch 28 in this position the circuit to the headlights is as follows: battery I0, conductor II, switch 28, contact 29, conducipr I44, movable contact 32 of foot switch 34, fixed contact 34, conductor I46, fixed contact I48, bridging contact 54, fixed contact I50, conductor 86, upper beam filament I4 of left headlight I2, and back to the battery through the ground; from conductor I46 to conductor I52, fixed contact I54, bridging contact 50, fixed contact I56, conductor IIB, upper beam filament 20 of right headlight I8, and back to the battery through the ground. If foot switch 30 is depressed to move contact 32 out of engagement with fixed contact 34 and into engagement with fixed contact 35 the circuit from movable contact 32 is the following: fixed contact 36, conductor I 58, fixed contact I 60, bridging contact 52, fixed contact I62, conductor I00, lower beam filament I6 of left headlight I2, and back through the ground. From conductor I58 a circuit is also completed as follows: conductor I64, fixed contact I66, bridging contact 48, fixed contact I68, conductor I24, lower beam filament 22 of right headlight I8, and back through the ground. If the direction signal indicator is actuated to indicate a left turn with the lights on and with foot switch 30 in the position shown so as to put the upper beam filaments in the circuit, bridging contact 50 is moved out of engagement with contacts I54-I 56 and into engagement with contacts I54a-I 56a, maintaining the circuit to upper beam filament 20 of right headlight I8 because contacts I54a and I56a are electrically connected to contacts I54 and I56, respectively. However, contact 54 moves out of engagement with fixed contacts I48-I50 and into engagement with contacts 82-84. Similarly, bridging contact 52 moves out of engagement with fixed contacts I60-I62, and into engagement with contacts 96-438. The shift in bridging contacts 52 and 54 takes the two filaments of left headlight I2 out of connection with the aforesaid circuit through foot switch 30 and puts them into the above described circuits with interrupter 56. It should be noted likewise that because of the shift to the left of bridging contact 44 the circuit to right rear signal light 26 is broken and this light goes off. Similarly, the leftward shift of bridging contact 46 breaks the circuit to left rear signal light 24. However, bridging contact 44 now bridges fixed contacts I04 and I06 completing an intermittent circuit to left rear signal light 24 which is the same circuit as was described above in connection with the operation with light switch 28 in its off position. If a left turn is indicated with foot switch 30 depressed so that the lower beam filaments are energized, the leftward shift of bridging contact 48 out of engagement with fixed contacts I66-I 68 and into engagement with contacts l66a--I68a, makes no change in the condition of the right headlight. However, this leftward shift of bridging contacts 52 and 54 again puts left headlight I2 in circuit with interrupter 56, as described above, causing alternate energizing of the two filaments.

If a right turn is indicated with the lights on and foot switch 30 in the position shown, the rightward movement of bridging contact 54 takes contact 54 out of engagement with contacts I48 I50 and into engagement with contacts I 48a- I50a. Since contacts I48a and I50a are connected to contacts I46 and I50, respectively, the

condition of left headlight I2 is not changed.

However, the rightward movement of bridging contacts 48 and 50 takes the upper and lower beam filaments out Of connection with their respective circuits through foot switch 30 and puts them into the abov described circuits of interrupter 56. As before, the rightward movement of contacts 44 and 46 breaks the circuit to the rear signal lights; left rear signal light is entirely disconnected, and right rear signal light is put in circuit with interrupter 56 as described above. With foot switch 30 depressed, indication of a right turn puts the right headlight into the circuits of interrupter 56 as before. However,

the rightward movement of contact 52 takes this contact out of engagement with fixed contacts Hill-I62 and into engagement with contacts IIiIla--I62a. Since contacts Him: and IBM are directly connected to contacts I66 and I62, respectively, there is no change in the condition of the left headlight.

By way of summary, the operation in general terms is as follows: If the direction signal switch is actuated with the lights off the headlight goes on on the side toward which the turn is contemplated. Instead of burning steadily, however, it flashes. This flashing is accomplished by alternately energizing the upper and lower beam filaments. The rear signal light on the side toward which a turn is to be made merely flashes on and off. If the direction signal switch is actuated with th parking lights on the parking lights are not affected and the tail and headlights are energized the same as with the light switch in-its off position. The signal light on the side toward which the turn is to be made flashes on and off as before and the other rear signal light goe off and stays off. If the direction signal switch is actuated with the headlights on the headlight on the side toward which the turn is to be made is caused to flash by alternate energizing of the filaments. The headlight on th other side remains unaffected whether its upper or its lower beam filament was energized at the time the direction indicator switch was actuated. With either parking or headlights on, the rear signal light on the side toward which the turn is to be made flashes on and off and the other rear signal light goes off and stays off.

It will be evident to those skilled in the art that changes and modifications in my invention may be made but I aim to cover the true scope of my invention in the appended claim.

I claim:

In a lighting system for vehicles, right and left headlights each having an upper beam, filament and a lower beam filament, a battery, a first circuit for energizing said headlight filaments ineluding said battery, a main switch for turning said circuit on and off, and a beam control switch for selectively connecting said circuit to either said upper or lower beam filaments, a second circuit for energizing said headlight filaments including said battery and a periodic interrupter switch for alternately connecting said second circuit to the upper and lower beam filaments of said headlights, and a selector switch interposed in said circuits between said beam control and periodic interrupter switches and said headlight filaments with circuit connections to said filaments controlled by movement of said selector switch, said selector switch having one position in which the upper and lower beam filaments of both headlights are connected in said first circuit and movable to selective positions in which the upper and lower beam filaments of either the right or left headlight are disconnected from said first circuit and connected in said second circuit to alternately energize said upper and lower beam filaments of said one headlight as a direction signal with the filaments of the other headlight connected in said first circuit and controlled by said main switch and beam control switch.

LUCIAN B. SMITH. 

